UV unwrap doesn't show faces in UV image editor
You have several objects selected and then you have gone into edit mode on one object, the active one. This is evident by the fact that the entire ship appears to be selected (from the orange outline) yet it's vertex data is not shown. This may be misleading you if you expect the entire ship to show in the UV editor.

Only the selected faces of the active object will show in the UV editor, in your screen shot you only have 2 vertices selected, which is why no UV faces of the object are shown. Press AA to de-select the two vertices and then select all of the vertices in the active object, then unwrap and then they will show spread out in the UV editor.

You will need to repeat this for each object unless you wish to join them together into one.